$10 \cdot f(7) + 9 \cdot g(-1) = $
Find ${f(7)}$ and ${g(-1)}$. ${2}$ ${4}$ ${6}$ ${8}$ ${\llap{-}4}$ ${\llap{-}6}$ ${\llap{-}8}$ ${2}$ ${4}$ ${6}$ ${8}$ ${\llap{-}4}$ ${\llap{-}6}$ ${\llap{-}8}$ $y$ $x$ ${y = f(x)}$ ${y = g(x)}$ ${f(7) = -1}$ ${2}$ ${4}$ ${6}$ ${8}$ ${\llap{-}4}$ ${\llap{-}6}$ ${\llap{-}8}$ ${2}$ ${4}$ ${6}$ ${8}$ ${\llap{-}4}$ ${\llap{-}6}$ ${\llap{-}8}$ $y$ $x$ ${y = f(x)}$ ${y = g(x)}$ ${g(-1) = 1}$ $ 10 \cdot {f(7)} + 9 \cdot {g(-1)} = 10({-1}) + 9({1}) $ $= -10 + 9$ $= -1$